Hypercholesterolemia is known to be one of the prime risk factors for ischemic cardiovascular disease, such as arteriosclerosis. Bile acid sequestrants have been used to treat this condition; they seem to be moderately effective but they must be consumed in large quantities, i.e. several grams at a time and they are not very palatable.
MEVACOR.RTM. (lovastatin), now commercially available, is one of a group of very active antihypercholesterolemic agents that function by limiting cholesterol biosynthesis by inhibiting the enzyme, HMG CoA reductase. In addition to the natural fermentation products, mevastatin and lovastatin, there are a variety of semi-synthetic and totally synthetic analogs thereof.
The naturally occurring compounds and their semi-synthetic analogs have the following general structural formulae: ##STR2## wherein: R.sup.1 is hydrogen, C.sub.1-5 alkyl or C.sub.1-5 alkyl substituted with a member of the group consisting of phenyl, dimethylamino, or acetylamino.
U.S. Pat. No. 4,517,373 discloses semi-synthetic hydroxy containing compounds represented by the above general formula wherein R.sup.* is ##STR3##
U.S. Pat. No. 4,537,859 and U.S. Pat. No. 4,448,979 also disclose semi-synthetic hydroxy containing compounds represented by the above general formula wherein R.sup.* is ##STR4##
These compounds are prepared by the action of certain microorganisms on the corresponding non-hydroxylated substrates. One such organism described in U.S. Pat. No. 4.537,859 is of the genus Nocardia.
U.K. Patent No. 2,075,013 discloses semi-synthetic hydroxy containing compounds represented by the above general formula wherein R.sup.* is: ##STR5## wherein R.sup.1 is H or Me, and R.sup.2 is H or acyl.
U.S. patent application Ser. No. 254,525 filed Oct. 6, 1988 now U.S. Pat. No. 4,940,727 discloses 6-substituted compounds of the above general formula wherein R.sup.* is: ##STR6## wherein R is ##STR7## and R.sup.1, R.sup.4, R.sup.7, R.sup.8 and R.sup.9 are broadly defined organic moieties.
U.S. Pat. Nos. 4,604,742 and 4,733,003 disclose compounds of the above formula wherein R.sup.* is: ##STR8## wherein X represents a hydrogen atom or a 2-methylbutyryl group, Y represents a hydrogen atom or a methyl group and R.sup.1 and R.sup.2 are the same or different and each represents an oxygen atom or a group of formula .dbd.N--OR.sup.3 where R.sup.3 is a hydrogen or alkyl moiety.
Copending U.S. Patent application Ser. No. 213,010 filed June 29, 1988 discloses 5-oxygenated compound of the above general formula wherein R.sup.* is ##STR9## R.sup.4 is H, alkyl or substituted alkyl and R.sup.5 and R.sup.6 are H, OH or OR.sup.7 where R.sup.7 represents a phosphoryl or acyl moiety.
Copending U.S. patent application Ser. No. 161,579 filed Feb. 29, 1988 now U.S. Pat. No. 4,855,456 discloses epoxide containing compounds wherein R.sup.* is: ##STR10## Z is I, Br or Cl.
Copending U.S. patent application Ser. No. 161,529 filed Feb. 29, 1988 now U.S. Pat. No. 4,894,466 discloses hydroxy containing compounds of the above general formula wherein R.sup.* is: ##STR11##